# naginterfaces.library.interp.dim1_​ratnl_​eval¶

naginterfaces.library.interp.dim1_ratnl_eval(a, u, x)[source]

dim1_ratnl_eval evaluates continued fractions of the form produced by dim1_ratnl().

For full information please refer to the NAG Library document for e01rb

https://www.nag.com/numeric/nl/nagdoc_29/flhtml/e01/e01rbf.html

Parameters
afloat, array-like, shape

must be set to the value of the parameter in the continued fraction, for .

ufloat, array-like, shape

must be set to the value of the parameter in the continued fraction, for . (The element is not used).

xfloat

The value of at which the continued fraction is to be evaluated.

Returns
ffloat

The value of the continued fraction corresponding to the value of .

Raises
NagValueError
(errno )

corresponds to a pole of , or is very close. .

Notes

dim1_ratnl_eval evaluates the continued fraction

where

and

for a prescribed value of . dim1_ratnl_eval is intended to be used to evaluate the continued fraction representation (of an interpolatory rational function) produced by dim1_ratnl().

References

Graves–Morris, P R and Hopkins, T R, 1981, Reliable rational interpolation, Numer. Math. (36), 111–128